2.Smallest Subarray with a given sum(easy) 2.1 问题描述 2.2 解决方法 2.3 代码 3.课后回顾 4.参考链接 sliding window pattern 1.原理描述 滑动窗口模式(sliding window pattern)是用于在给定数组或链表的特定窗口大小上执行所需的操作,比如寻找包含所有 1 的最长子数组。从第一个元素开始滑动窗口并逐个元素...
使用一个字典保存数组某个位置之前的数组和,然后遍历数组求和,这样当我们求到一个位置的和的时候,向前找sum-k是否在数组中,如果在的话,更新结果为之前的结果+1。同时,当前这个sum出现的次数就多了一次。 和560. Subarray Sum Equals K几乎一模一样的题目,为什么就是不会做呢? classSolution(object):defnumSubarr...
第一种是prefix sum + 双指针。 例如Minimum Size Subarray Sum - LeetCode: Given an array of n positive integers and a positive integers, find the minimal length of a contiguous subarray of which the sum ≥s. If there isn't one, return 0 instead. 用O(N)时间得到一个prefix sum array,可...
这题可以利用HashMap,把出现过的sum 当作key 存入, 把这个sum 出现过的次数 当作value 存入。 遍历nums array,一直更新sum,然后去map 里找有没有 sum - k,有的话说明 sum - k 是一个旧的sum,之前出现过。换句话说,新的sum - 旧的sum = k,说明 新的sum 减去 旧的sum,剩下的那一段的 和 等于k, ...
LeetCode-Binary Subarrays With Sum Description: In an array A of 0s and 1s, how many non-empty subarrays have sum S? Example 1: Input: A = [1,0,1,0,1], S = 2 Output: 4 Explanation: The 4 subarrays are bolded below:
Given an array A of integers, return the number of (contiguous, non-empty) subarrays that have a sum divisible by K.Example 1:Input: A = [4,5,0,-2,-3,1], K = 5Output: 7Explanation: There are 7 subarrays with a sum divisible by K = 5:[4, 5, 0, -2, -3, 1], [5]...
well, this problem aims to return the length of the shortest subarray of A with sum at least K. so let’s assume B is the accumulate array A. so which means we need to find the closest l~r which sum(A[l:r]) >= K, so => B[r] - K >= B[l], so if B[l] is fixed,...
1186 Maximum Subarray Sum with One Deletion 删除一次得到子数组最大和 Description: Given an array of integers, return the maximum sum for a non-empty subarray (contiguous elements) with at most one element deletion. In other words, you want to choose a subarray and optionally delete one element...
992 Subarrays with K Different Integers K 个不同整数的子数组 Description: Given an integer array nums and an integer k, return the number of good subarrays of nums. A good array is an array where the number of different integers in that array is exactly k. ...
Given a 0-indexed integer array nums, determine whether there exist two subarrays of length 2 with equal sum. Note that the two subarrays must begin at different indices.Return true if these subarrays exist, and false otherwise.A subarray is a contiguous